Intel's D5400XS: The Best Multi-GPU Motherboard?

Despite our rant about Fully Buffered DIMM, the D5400XS is actually a very impressive motherboard. It all starts with the fact that the D5400XS supports both SLI and Crossfire.

Don't be fooled, there's no technical reason why SLI can't work on all current Intel chipsets. NVIDIA's public argument for why it isn't enabled is because NVIDIA goes through a lot of internal testing to make sure that SLI works as best as possible with its own platforms, putting Intel platforms through the same tests isn't very high on NVIDIA's list of priorities.

The reality is that SLI is a very important brand to NVIDIA and simply giving away support just isn't going to happen. Intel and NVIDIA have never been able to come to terms on a licensing agreement to gain SLI support on Intel chipsets. It's not hard to understand why; if NVIDIA enabled SLI support on Intel chipsets, there would be absolutely no reason to buy NVIDIA based motherboards. With AMD already working against NVIDIA to make sure its own chipsets are the most desirable for its CPUs, it's not too hard to see why NVIDIA wants to hold onto the only reason to buy a nForce Intel chipset.

Because of the small production numbers however, Skulltrail makes the perfect platform for SLI support. There's still no licensing agreement in place, but the D5400XS motherboard uses two NVIDIA PCIe 1.1 bridges that each take 16 PCIe lanes coming off of the MCH and make two x16 slots out of them.

The two NVIDIA MCPs

There are four usable PCIe x16 slots on the motherboard, which should be able to support 2, 3 or 4 way CrossFire X down the road.

With NVIDIA silicon on board, the NVIDIA graphics drivers don't have to do anything funny to enable SLI support - it just works. It is worth noting that only 2-way SLI will work on the D5400XS, 3-way and 4-way configurations are not and never will be supported according to NVIDIA. After all, higher end SLI customers would be the target market for a Skulltrail system and you definitely don't want to make them too happy with an Intel chipset.

We ran a couple of quick tests to make sure that SLI scaling was on par with NVIDIA's own chipsets. The results were as expected, the D5400XS scales from one to two NVIDIA GPUs just as well as the nForce 780i:

Now you can see why NVIDIA doesn't want to enable SLI on more Intel chipsets. It's odd that it has taken a high end, two socket enthusiast motherboard to become the ideal multi-GPU desktop platform but we'll take what we can get. We finally have a motherboard that doesn't tie your hands when it comes to graphics upgrade path. Kudos to Intel for making it happen, but it's a shame that we'll probably never see it on another motherboard.

ncG1vNJzZmivp6x7orrAp5utnZOde6S7zGiqoaenZH91f5Roaw%3D%3D